The one I tried yesterday was https://www.hackerrank.com/challenges/ctci-array-left-rotation
Following was my initial solution. It's kind of brute-force algorithm for shift things left, but anyway...
package main
import (
"fmt"
"strings"
"bufio"
"os"
"bytes"
)
func main() {
var len, nToRotate int
var input string
var buffer bytes.Buffer
fmt.Scanln(&len, &nToRotate)
scanner := bufio.NewScanner(os.Stdin)
for scanner.Scan() {
buffer.WriteString(scanner.Text())
}
input = buffer.String()
var items []string
items = strings.Fields(input)
//fmt.Printf("%d", len(items))
for i := 0; i < nToRotate; i++ {
items = append(items[1:], items[0])
}
fmt.Println(strings.Join(items[:]," "))
}
My code passed the test when I clicked "Run Code", but it's failing unit test 6, 8, 9 when submitting the code. Those 6, 8, and 9 is pretty long one line input string and I was wondering if it's some kind of timeout or library error due to input string size.
After hours of investigation and asking questions to other GoLang experts ( than me ), I was able to pass all the tests and submitted the solution. Here is my answer. I changed algorithm a bit to be more time/space efficient as well. Check the highlighted line which was the solution of Runtime Error in Hackerrank page.
package main
import (
"fmt"
)
func main() {
var (
length, nToRotate int
)
fmt.Scanln(&length, &nToRotate)
items := make([]string, length)
for i := 0; i < length; i++ {
fmt.Scan(&items[i])
}
items = ShiftLeft(items, nToRotate)
for i := 0; i < len(items); i++ {
fmt.Printf("%s ", items[i])
}
}
func ShiftLeft(items []string, nToRotate int) []string {
var (
i, j, k int
temp string
)
size := len(items)
for i = 0; i < gcd(nToRotate, size); i++ {
temp = items[i];
j = i
for {
k = j + nToRotate
if k >= size {
k = k - size
}
if k == i {
break
}
items[j] = items[k]
j = k
}
items[j] = temp
}
return items
}
func gcd(x, y int) int {
for y != 0 {
x, y = y, x % y
}
return x
}
And I just found that someone already had same issue (of course) with Go, and opened issue at GoLang's GitHub page. Check those conversation if you want to understand more about the issue.
https://github.com/golang/go/issues/17910
